Module 1 - CVS Flashcards
Functions of the CVS
- Transport
- Homeostasis
- Protection (Immune Response)
Structures of the CVS
- Blood,
- Heart,
- Blood Vessels (Arteries, Capillaries, Veins)
Arteries
Carry blood away from heart
Veins
Return blood towards the heart
Capillaries
Exchange of gases, nutrients and waste products between blood and tissues
Heart
Muscular pump that establishes pressure gradient for blood flow
Heart Chambers
Left Atrium, Left Ventricle, Right Atrium, Right Ventricle
Septum
Dividing wall between left and right sides of heart
Pericardium
Double-walled sac containing the heart and major blood vessels
True/False? - Deoxygenated and Oxygenated Blood Mix in a Healthy Heart
False
Coronary Arteries
Wrap around the heart and transport oxygen to heart
Coronary circulation
Provides blood to the heart to allow it to pump
Functions of Pericardium
- Maintains heart position,
- Prevents heart from overfilling
Layers of Pericardium
- Outer fibrous pericardium,
- Inner serous pericardium (parietal and visceral layer)
Location of parietal cavity
Between the 2 serous layers
Which ventricle has a thicker wall? Why?
The left ventricle as it operates at a higher pressure due to pumping blood to entire body minus the lungs
Pulmonary Circulation
- Blood supply to Lungs
- Operatesat low pressure
- Right side of heart
- Low O2 in Arteries, High O2 in Veins
Systemic Circulation
- Blood supply to the Rest of the body minus the lungs
- High pressure
- Left side of heart
- High O2 in Arteries, Low O2 in Veins
Deoxygenated Blood Pathway
Blood enters via the inferior (lower body) and superior (upper body) vena cava where it then enters the right atrium. Blood flows through the tricuspid valve into the right ventricle. Right ventricle contracts and pumps blood through the pulmonary valve into the pulmonary artery, whereby it is carried from the heart to the lungs. In the lungs, the deoxygenated blood undergoes gas exchange in the capillaries where carbon dioxide is exchanged for oxygen.
Oxygenated Blood Pathway
Oxygenated blood is carried by the pulmonary veins from the lungs to the left atrium. The oxygenated blood flows through the bicuspid/mitral valve into the left ventricle. The left ventricle contracts and pumps blood through the aortic valve into the aorta. The aorta carries the oxygenated blood to the rest of the body.
Branches of the Aortic Arch
- Brachiocephalic Trunk (supplies blood to right arm and right side of head and neck)
- Left common carotid artery (supplies blood to left side of head and neck)
- Left subclavian artery (blood to the left arm)
Papillary Muscles
Muscles in the ventricles to prevent valves from opening during contraction. Attached to Atrioventricular valves via chordae tendineae.
Semilunar Valves
Pulmonary Valve and Aortic Valve
Atrioventricular Valves
Tricuspid Valve and Bicuspid Valve
What is the direction of blood flow?
Unidirectional! Blood must flow through each circuit before returning to the heart
Arterioles
Smallest arteries branch into arterioles. Join the arteries to capillaries. Control blood flow and pressure.
Venules
Collect blood from the capillaries and join to veins which carry the blood back to the heart. Venules carry wastes from tissues.
Functions of the Heart
- Pumping Blood
- Oxygen Delivery
- Nutrient Transport
- Waste Removal
- Circulatory Regulation
- Hormone Transport
- Immune Response
- Thermoregulation
- Gas Exchange
- Homeostasis
Systole
When heart contracts to pump blood out.
Diastole
When the heart relaxes after contraction (filling).
Events in Cardiac Cycle
Closely integrated system of alternately contracting and relaxing in a rhythmic and coordinated sequence.
True/False? - Blood always flows from a region of higher to lower pressure
True
True/False? - Heart valves are either open or closed depending on relative pressures on either side of the valve
True
Heart Sounds
S1: Closure of the bicuspid and tricuspid valves
S2: Closure of aortic and pulmonary valves
S3: Marks end of filling phase
S4: Atrial contraction but normally not heard